Pressure bulkheads in aircraft serve to bound an internal cabin and/or a freight compartment relative to the external environment. Conventionally they are arranged in passenger aeroplanes in the vicinity of the cockpit, i.e. in the region of a nose radar antenna, and at the rear, i.e. in the region of the tail unit. Most pressure bulkheads are designed in the shape of a dome with a curved skin. This has the advantage that the skin is loaded solely as a membrane, as a result of which the skin can be designed to be very thin. In particular in pressure bulkheads of fiber-reinforced composite materials, the skin can thus be built up from a very few laminate layers, as a result of which the weight of the pressure bulkhead can be radically reduced. What is disadvantageous, however, is the relatively large installation space required in the longitudinal direction of the aircraft. This amounts to approximately 25% of the radius of the pressure bulkhead. Typical depths for a single aisle aeroplane are some 400 mm to 500 mm.
In addition, metallic pressure bulkheads with a flat skin are known. For purposes of stabilizing the skin these have a multiplicity of stiffeners arranged orthogonally relative to one another. The stiffeners form a multiplicity of intersection regions, which in particular when using a differential form of construction represent weak points in structural mechanics terms. Furthermore, as a result of their orthogonal arrangement relative to one another the stiffeners are not optimally orientated in terms of loading. In particular the accommodation of bending moments is problematical, so that this type of pressure bulkhead has a relatively thick skin and a relatively high number of stiffeners, which not only leads to a high weight, but also to a complex assembly. While it is possible for purposes of optimizing the intersection regions to design the pressure bulkhead as an integral metal form of construction, for example, with a multiplicity of stiffeners milled out of a solid metallic plate, this type of production is very cost intensive.
A flat, or essentially flat, pressure bulkhead with stiffeners oriented optimally in terms of loading is shown, for example, in the application U.S. Pat. No. 6,443,392. The pressure bulkhead has a multiplicity of stiffeners on a skin, extending radially from a central intersection region. For additional stabilization of the skin and also the stiffeners two ring elements are provided, radially spaced apart from one another, which are connected with the stiffeners, or are integrated with the latter in sections. What is problematical in this pressure bulkhead, however, now as before, is the accommodation of bending moments and moreover, the integration of the at least one ring element into the stiffeners, or the integration of the stiffeners into the at least one ring element.